Lee In-Seon, Kim Kyuseok, Park Hi-Joon, Lee Hyangsook, Jung Won-Mo, Kim Do-Won, Chae Younbyoung
Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 02447, Korea.
Department of Ophthalmology, Otorhinolaryngology and Dermatology of Korean Medicine, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea.
Brain Sci. 2021 Mar 29;11(4):438. doi: 10.3390/brainsci11040438.
Itch is an unpleasant sensation associated with an urge to scratch and is a major health care issue associated with atopic dermatitis (AD). Contagious itch, i.e., subjective feelings of itchiness induced by watching others' scratching behavior, is common in patients with AD. Using electroencephalography, we examined alpha (8-13 Hz) oscillations in sensorimotor areas associated with the desire to scratch in patients with AD.
Thirty-six patients with AD and 34 healthy controls (HCs) participated in this study. They evaluated their itch levels after watching short videos of a model scratching or tapping parts of his body. Neural oscillations were recorded from nine electrodes, including those placed over sensorimotor areas. Time-frequency analysis was used to compare mu rhythm suppression over the sensorimotor areas in response to these videos between patients with AD and HCs.
The behavioral test showed that the visual stimuli induced increased feelings of itchiness in patients with AD relative to HCs under the tapping and scratching conditions. The time-frequency analysis revealed that mu rhythm suppression in response to scratching images was significantly prominent in patients with AD, but not in HCs.
Patients with AD exhibited increased susceptibility to contagious itch. This phenomenon might be related to enhanced mu rhythm suppression in sensorimotor areas of the brain in these patients. Our findings provide new insight into the neurophysiological basis of itch sensations in patients with AD.
瘙痒是一种伴有搔抓冲动的不愉快感觉，是特应性皮炎（AD）相关的一个主要医疗问题。传染性瘙痒，即通过观察他人搔抓行为诱发的主观瘙痒感，在AD患者中很常见。我们使用脑电图检查了AD患者中与搔抓欲望相关的感觉运动区域的α（8 - 13赫兹）振荡。
36例AD患者和34名健康对照者（HCs）参与了本研究。他们在观看一个模型搔抓或轻拍身体部位的短视频后评估自己的瘙痒程度。从包括置于感觉运动区域上方的9个电极记录神经振荡。使用时频分析比较AD患者和HCs对这些视频在感觉运动区域的μ节律抑制情况。
行为测试表明，在轻拍和搔抓条件下，视觉刺激相对于HCs在AD患者中诱发了更强的瘙痒感。时频分析显示，AD患者对搔抓图像的μ节律抑制显著突出，而HCs则不然。
AD患者对传染性瘙痒的易感性增加。这种现象可能与这些患者大脑感觉运动区域增强的μ节律抑制有关。我们的发现为AD患者瘙痒感觉的神经生理基础提供了新的见解。
